Field-magnet for dynamos



(No Model.)

G. E, DORMAN. FIELD MAGNET POR DYNAMOS.

Nn. 470,749t Patented Mar. 15, 1892.

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GEORGE EDENSOR DORMAN, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE STANDARD ELECTRIC COMPANY, OE ILLINOIS.

FIELD-MAGNET FOR DYNAMOS.

SPECIFICATION forming part 0f Letters Patent No. 470,749, dated March 15, 1892.

Application tiled December 17, 1890. Serial No. 874,994. (No model.)

To @ZZ whom it may concern:

Be it known that I, GEORGE EDENsoR Don- MAN, a subject of the Queen of Great Britain, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Field-Magnets for Dynamo-Electric Machines, of which the following is a full, clear, and exact specification.

My invention relates to improvements in the fieldmagnets of dynamo -electric machines, and has for its object to provide certain new and useful features more particularly illustrated in the accompanying drawings, wherein- Figure l is an end view of a iield-magnet. Fig. 2 is a side view of a portion thereof. Fig. 3 represents a side and end view of a section or segment.

Lilie parts are indicated by the same letters or numerals in all the figures.

A A are series of segments or sections provided each with the curved body portion and the inwardly-projecting ends B B, radial to the arc of the body of the segment A.

C C Aare bolt-holes through such segments to receive the bolts D D, which are provided with the countersunk heads E E, received into suitable recesses in the circular end portions F of the field-magnets. These end portions are provided with the legs G. The end portion of course must be of the outline of the field-magnet in cross-section, or, as in the present case, must be circular, and in order to constructa field-magnet of theparts herein shown it is only necessary to place alternate sections or segments A upon one of these end pieces F and then to place suitable bolts D D through the appropriate holes C C i'n such segments. Thus we would lay down first the segments 3 3 3 3, which are shown in full lines and are supposed to be next to the end piece F. These sections or segments are indicated in Fig. l in full lines. "We now place alternate sections 4L 4, (shown partly in dotted lines in Fig. 1,) the end portions B B of Vwhich are in alignment with the end portions of the segments 3 3. These segments of course also receive the bolts D D, and in like manner successive overlapping sections are built up until the field-magnet has reached the desired length, whereupon the ends ot the bolts D D will be suitably secured to or in a similar end piece to that shown in the drawings. lVhen thus completed, we have a field-magnet of iat successive segments with inwardlyprojecting pole-pieces made up each of thin sheets, all in alignment and all radial to the general ou tline of the Held-magnet. Such a field-magnet so formed will be in the form of a cylinder with inwardly-projecting oblong substantially-solid pole-pieces andan exterior cylindrical portion open-worked or slotted, as shown in Fig. 2. The end pieces E F would preferably be of cast-iron, while the segments out of which the field-magnet is constructed would preferably be thin sheets of wrought-iron.

I claim-- l. In a dynamo-electric machine, a series of short overlapping` arc-shaped segments with inwardly-projecting ends in alignment, so as to form a circular held-magnet with inwardlyprojecting pole-pieces.

2. In a dynamo-electric machine, a series of short overlapping arc-shaped segments with inwardly-projecting ends in alignment, so as to form a circular field-magnet with inwardlyprojecting pole-pieces, and transverse bolts passing through such segments and polepieces,so as to securely connect the whole together.

3. In a dynamo-electric machine, a fieldmagnet consisting of a series of curved segments with inwardly-projecting ends in alignment with each other, so as to form inwardlyprojecting pole-pieces for carrying the fieldmagnet coils, and transverse bolts passing through such segments and pole-pieces, so as to securely connect the whole together.

et. In a dynamo-electric machine, a fieldmagnet consisting of a series of segments alternately overlapping at the ends and provided with inwardly-projecting ends placed in alignment, so as to form inwardly-projecting pole-pieces, such segments secured together by bolts which pass through them, so as to form an open-work or slotted supporting portion with inwardly-projecting substantially-solid pole-pieces.

GEORGE EDEUSOR DORMAN,

Witnesses:

CELESTE P. CHAPMAN, HAREIET M. DAY. 

